This is very nice.... in principle. It solves the problem with the exit radiation. The protons only penetrate to a certain (selectable) depth. Therefore there is much less tissue damage.
On the other hand there are just VERY few places (6?) where they do this (as opposed to IMRT). I am not aware if there are results for sizeable cohort (Brian?). I tried to look into this and my GP and myself contacted the FL center.... no response.

Timeliness of the treatment and accessibility are major concerns and may negate potential advantages of proton therapy!

M